Devices that help pilots fly aircraft in unusual environments and circumstances are necessary as the performance characteristics of aircraft steadily increase. An example of one such device is described in U.S. Pat. No. 5,353,226, issued to D. W. Repperger on May 7, 1996 and entitled, "Coriolis Indicator For Situational Awareness." The device described in this U.S. Patent uses measurements of angular rates (aircraft body axis rates) and an indicator to detect the existence of Coriolis accelerations which may not be immediately obvious to a pilot. The presence of Coriolis accelerations affects a pilot's perception of aircraft attitude and spatial orientation, thus potentially affecting the safety of the pilot.
Another example of a pilot assistance device is described in U.S. Pat. No. 5,629,848, issued to Repperger et al on May 13, 1997 and entitled, "Spatial Disorientation Detector." This detector senses important acceleration fields that are known to produce spatial disorientation to a pilot. This detector utilizes implicit models of the human vestibular system and a Kalman filter estimator to examine when adverse environmental influences may exist, even though these influences may not be readily detected by the pilot.
Examples of other pilot assistance devices and/or methods are found in the following articles: R. F. Stengel, "Toward Intelligent Flight Control," IEEE Transactions on Systems, Man, and Cybernetics, vol. 23, No. 6, November/December 1993, pp. 1699-1717; T. B. Sheridan and W. R. Ferrell, "Man-Machine Systems: Information, Control, and Decision Models of Human Performance," The MIT Press, Cambridge, Mass., 1974; R. A. Hess, "Effects of Time Delays on Systems Subject To Manual Control," J. Guidance, July-August, 1984, pp. 416-421; and R. A. Hess, "Technique For Predicting Longitudinal Pilot-Induced Oscillations," J. Guidance, vol. 14, no. 1, 1990, pp. 198-204.
There still exists a need in these arts to not only notify the pilot of adverse conditions, but also to assist the pilot in tracking tasks. These tasks include pursuit or chase of another aircraft wherein the minimization of the error between position and orientation of the two aircraft is critical, following a specified flight trajectory or flight path, or following a specified terrain or runway. The present invention addresses this need.